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Chapter 14
The Era of Hydrodiascopes
The Era of Hydrodiascopes
Introduction
Towards the end of the 19th century, contact lenses and contact shells (1) were relegated
for a period to a subsidiary position by hydrodiascopes. This term was a shared
designation for Czermak’s orthoscope, so-called water cases, water chambers and waterfilled goggles, all of the above being equipped with corrective lenses. (2)
In 1851, Czermak had achieved neutralization of corneal refractive power and
elimination of the corneal reflex by contact of the eye with a liquid contained in a glass
box. His “orthoscope” was originally intended for scientific use, but had been adapted
for diagnostic use in the clinic by Hasner and by Coccius. The orthoscope could be
tolerated by a patient for several minutes and facilitated the examination of the anterior
segment of the eye. (3)
Czermak’s publication would probably have passed by unnoticed, as had Hasner’s, had
not Helmholz revived interest in the orthoscope in his textbook on physiological optics
successive editions (4), which had served as a textbook for generations of medical
students and physicians. Helmholz’s reference textbook included a detailed description
of Czermak’s orthoscope and was also illustrated with a copy of the diagram of this
instrument. Furthermore, the orthoscope, as described by Czermak, remained an
instrument for scientific use, notwithstanding various later modifications made by
physicians for diagnostic purposes, e.g., by Hasner. Other modifications were also made
for experiments with ocular fundus photography.
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The Era of Hydrodiascopes
1 - Source documents
Year
1896
1897
1898/99
1906
Publication
Lohnstein (Berlin): "Zur Gläserbehandlung des unregelmässigen
Hornhautastigmatismus" (Concerning the Treatment of Irregular Corneal
Astigmatism by Glasses)
Lohnstein (Berlin): "Die Berechnung der Planoconvex Linse des Hydrodiaskops"
(Calculation of the Plano-convex Lens of the Hydrodiascope)
Majewski (Krakow): "Ueber corriegierende Wirkung des Hydrodiaskops
Lohnsteins in Fällen von Keratokonus und unregelmäßigem Astigmatismus"
(Concerning the Corrective Effect of Lohnstein's Hydrodiascope in Keratoconus
and Irregular Astigmatism)
Fater/Siegrist (Berne): "Hydrodiaskop und Keratoconus" (Hydrodiascope and
Keratoconus)
Table 14 - 1
Early communications and publications on hydrodiascopes (1896-1917).
In the course of the adaptation of the hydrodiascope for clinical use in the correction of
keratoconus, several steps can be distinguished and these provide the framework for the
source documents making up this chapter:
in 1896, Lohnstein described the hydrodiascope,
in 1898, Majewski adapted the hydrodiascope for binocular use,
from 1898 to 1916, Siegrist used the hydrodiascope for clinical purposes.
1.1 - Lohnstein’s Hydrodiascopes (1896 -1897)
1.1.1 - First Description (1896)
Figure 14-1
Title of Lohnstein's publication on the orthoscope.
Lohnstein's publication: "Zur Gläserbehandlung des
unregelmässigen Hornhaut-Astigmatismus" (Concerning the
Treatment of Irregular Corneal Astigmatism by Glasses). It is the
first description of the therapeutic use in humans of a "water
case" (Wasserkasten) equipped with a corrective lens.
In 1896, the first description of the
therapeutic use in humans of an
orthoscope equipped with a corrective
lens was not the work of an
ophthalmologist but that of the general
medical practitioner Lohnstein of Berlin,
Germany. His published article had the
innocuous and inoffensive title “Zur
Gläserbehandlung des unregelmässigen
Hornhaut-Astigmatismus” (Concerning
the Treatment of Irregular Corneal
Astigmatism by Glasses).
Lohnstein’s Case History
Lohnstein was personally afflicted with
bilateral keratoconus. The results of the operative procedures recommended at the time
were extremely disappointing, whether cauterization of the corneal summit or optical
iridectomy. Lohnstein noted also in his paper the flagrant contradiction between the
success of the surgical techniques as proclaimed at the congresses and the sad reality. (5)
(LOHNSTEIN Th., "Zur Gläserbehandlung des unregelmâssigen HornhautAstigmatismus", Klinische Monatsblätter für Augenheilkunde, 34, 1896, 405-420. Page 405)
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The Era of Hydrodiascopes
From Concept to Practical Realization
As a physician, Lohnstein recalled his
practical studies in physiological optics
while a medical student, notably those
with Czermak’s orthoscope. He had noted
a temporary improvement in his visual
acuity:
“Everybody knows how Thomas Young
proved that the cornea did not participate
in accommodation when he placed a
water-filled vessel on his eye. Because the
cornea has a refractive index similar to
that of water and weak aqueous solutions,
one must thus have very significantly
reduced the influence of the irregular
corneal curvature. Furthermore, several
years earlier, I had established this with
my left eye by using Czermak’s
orthoscope.”
Figure 14-2
Lohnstein's hydrodiascope.
Schematic representation of the hydrodiascope constructed for
Lohnstein by the optician E. Sydow (Berlin) in 1896.
The hydrodiascope is fitted on the soft tissues of the orbital
periphery.
a Filling tube,
ß ß' Soft rubber border,
Lateral fixation ring for ribbon tied behind head.
(LOHNSTEIN Th., "Zur Gläserbehandlung des unregelmâssigen HornhautAstigmatismus", Klinische Monatsblätter für Augenheilkunde, 34, 1896, 405-420. Figure page 409).
“Bekanntlich hat Thomas Young die Nichtbeteiligung der Hornhaut bei der Accommodation dadurch
bewiesen, dass er ein mit Wasser gefülltes Gefäss vor das Auge brachte. Da die Hornhaut in ihrem
Brechungsindex vom Wasser und mässig concentrirten wässerigen Lösungen nicht viel verschieden ist, so
muss man - was ich übrigens schon vor mehreren Jahren mit dem Czermak’schen Orthoskop an meinem
linken Auge festgestellt hatte - in dieser Weise den Einfluss der unregelmässigen Hornhautkrümmung auf
ein sehr geringes Maas herabsrücken können.” (6)
The challenge consisted in constructing a hollow frame and finding a liquid that the eye
could tolerate for a lengthy period. Lohnstein approached Sydow, an optician in Berlin
who was a supplier to the ophthalmological clinics, by which reason he had a collection
of eyelid and orbital molds. Furthermore, he had already produced prosthetic frames
from these models:
“I turned […] to the well-known optician and mechanical engineer, Mr. Emil Sydow
(Berlin N.W.), who was kind enough to place his experience and skills at my disposal. It
worked out very conveniently that this individual was already in possession of a form of
frame used for other orders from ophthalmologists that was sufficient for my
requirements. My only remaining task was to determine the angle at which the lens
should be inclined against the axis of the frame, as well as deciding on the depth of the
frame and focal length of the lens.”
“Ich wandte mich [...] an den bekannten Optiker und Mekaniker Herrn Emil Sydow, Berlin NW., welcher
mir in dankeswerther Weise seine bewährte Kraft zur Verfügung stellte. Es traf sich günstig, dass derselbe
von anderen ophthalmologischen Aufgaben her bereits im Besitze einer Form der Fassung war, welche
den zu stellenden Ansprüchen durchaus genügte. Meine Aufgabe bestand also nur darin, den Winkel zu
bestimmen, in welchem die Linse gegen die Axe der Fassung geneigt sein musse (ca.20°), sowie nach
Festsetzung der Tiefe der Fassung, die Brennweite der Linse zu bestimmen.” (7)
The optician furnished Lohnstein with a model similar to the closed orthoscope of
Hasner and Coccius. This device consisted essentially of an oval monocular frame, the
back edge of which was fitted, above and below, to the periphery of the eyelids, with the
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The Era of Hydrodiascopes
temporal part wider than the nasal part. Soft rubber tubing covered the orbital border of
the frame, providing a certain water-tightness when the device was forcibly applied
against the skin. Two ribbons knotted behind the occipital protuberance held it there.
Filling was achieved through an orifice pierced in the upper portion of the frame, above
which there was a tube shut by an ebony stopper. The optician had set a plano-convex
lens, tilted at 20 degrees with reference to the axis of the device with its plano-surface
oriented towards the cornea.
The front convex surface of the hydrodiascope corresponded with the normal optics of
an eye in the primary position, there being 15.00 mm of separation from the summit of
the cornea to the back surface of the corrective lens. Lohnstein therefore chose a lens
with a focal length of 37.50 mm and, for practical purposes, this gave him the expected
visual correction. The visual improvement he achieved was accompanied by image
enlargement through a magnifying loupe effect together with constriction of the visual
field. A later improved model with the separation between cornea and corrective lens
reduced to 10.00 mm and a larger diameter for the corrective lens remedied these
undesirable features.
After five months of experimentation and the provision of a plano-convex lens of
adequate power, Lohnstein obtained a visual acuity in his right eye that was sufficient for
reading and for distance vision. The superposition of glasses with cylindrical lenses and
the addition of a diaphragm of 3.50 mm in diameter produced an almost normal visual
acuity for far and near vision.
Lohnstein, encouraged by these results in his first eye, went on to fit his more seriously
affected left eye. The visual acuity in this eye progressed from 1/18 to 2/8 or even 1/2 if
he added a plano-convex lens of 34.00-mm focal length. However, he noted the presence
of cloudiness in the location corresponding to the corneal leucoma. Nevertheless, he was
able to wear this device for periods of 30 to 90 minutes at a time and very occasionally
reached two hours of wearing time.
Liquid used for Filling the Device
The choice of liquid for filling the device was the subject of considerable thought and
the object of study in numerous trials. Physiological saline solution, at a temperature of
35 to 40 degrees, seemed the best tolerated of the available solutions and did not produce
any irritation, whether the eye was open or closed at the time of filling. A cold solution
was tolerated if one took the precaution of shutting the eyelids for several instants while
waiting for the liquid to warm up. The temperature came into equilibrium after about an
hour at 20° C, no matter whether it was poured in hot or cold:
“As far as the second point is concerned, i.e., the choice of liquid for filling the device, it
is more or less self-evident that I adopted saline solution, warmed this up to between 35
and 40 degrees and then introduced it into the device. In doing this, there was no trace of
irritation. Furthermore, it made no difference whether the eye was open or closed. Later
on, I determined that cooler solutions were equally well tolerated, except that one has the
same feeling as when cold water suddenly touches one’s skin. Furthermore, one can
reduce the initial irritation to a minimum by keeping the eye shut for a fraction of a minute
after the cold fluid contacts the upper lid. The liquid warms up at about 6° C an hour, as
I determined through measurement, and thus the temperature rises from 20° to 26°. When
the liquid reaches body temperature, it gradually cools down.”
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The Era of Hydrodiascopes
“ Was den zweiten Punkt, die Wahl der Flüssigkeit anbetrifft, so erscheint es fast selbstverständlich, dass
ich auf die physiologische Kochsalzlösung verfiel, die ich anfangs auf 35 bis 40° C erwärmt, in den
Apparat brachte. Es erfolgt in der Tat keine Spur einer Reizung. Es ist hierbei sogar gleichgültig, ob das
Auge bei der Einfüllung geschlossen ist oder nicht. Später stellte ich fest, dass kühlere Kochsalzlösungen
genau ebenso gut vertragen werden, nur hat man im ersten Moment dasselbe Gefühl, das man hat, wenn
kaltes Wasser plötzlich eine Hautstelle trifft. Uebrigens kann man den anfänglichen Reiz dadurch auf ein
Minimum reducieren, dass man das Auge noch einen Bruchteil einer Minute, nachdem die kalte
Flüssigkeit das obere Lid bespült, geschlossen hält. Die Flüssigkeit erwärmt sich, wie ich durch eine
Messung feststellte, innerhalb einer Stunde um etwa 6° C, also von 20° auf 26°, während sie sich, bei
Körpertemperatur eingebracht langsam abkühlt.” (8)
Lohnstein had tried saline solutions of various concentrations. Distilled water or strong
saline solution was irritating. A saline solution of 0.85% seemed the best tolerated.
Glucose solutions of up to 10% were well tolerated but had no advantage over saline
solutions. The refractive index of the ideal solution would have to be close to that of the
aqueous humor. Researching a solution of which the refractive index would be close to
that of the cornea would require a 20% glucose solution. This would be intolerable and
the beneficial effect illusory, as the optical power of a cornea is negligible when thinned
by keratoconus.
Lohnstein noted Fick’s error in claiming that a glucose solution of 2% possessed the
same refractive index as the corneal tissues:
“Fick’s statement that a 2% grape sugar solution had the same refractive index as
cornea is therefore not valid. Only a 20% grape sugar solution could come close to the
refractive power of the cornea.”
“Fick’s Angabe, wonach eine 2% Traubenzuckerlösung die gleiche Brechung wie die Hornhaut hat, trifft
also nicht zu. Erst eine etwa 20 %ige Traubenzuckerlösung dürfte an Brechkraft der Hornhaut
gleichkommen.” (9)
The question regarding the toleration of the osmolarity of such a solution was also
raised. The glucose solution would have to be isotonic with tears (310 mOsm/kg), and
this was reached with a glucose solution of approximately 5.25% but not with a 2%
solution (115 mOsm/kg).
Naming the Device
Lohnstein proposed to give his device the name “hydrodiascope,” this term being
derived from àäùñ (water), óêoðÝù (to see) and äiÜ(through):
“As everything requires a name, I must therefore be allowed to suggest the term
‘Hydrodiascope’ for my device, without attaching any special weight to this.”
“Da jedes Ding einen Namen haben muss, so möchte ich mir erlauben, für meinen Apparat die
Bezeichnung “Hydrodiaskop” vorzuschlagen, ohne indessen auf sie irgend welches Gewicht zu legen.”
(10)
Comparison of the Hydrodiascope with Fick’s “Contactbrille”
Lohnstein compared the properties of the hydrodiascope with those of Fick’s
“Contactbrille”. The two are based on the same principle of corneal optical
neutralization through contact with water, in which a new refractive entity replaces the
refractive power of the cornea that has been eliminated. However, according to
Lohnstein, Fick’s “Contactbrille” had the disadvantage of irritating both the eye and the
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The Era of Hydrodiascopes
eyelids, as well as requiring assistance by another person to place these devices into the
eye. Lohnstein insisted that he had never personally tried them out since they seemed to
him to be too risky, especially with keratoconus, because the contact lens could touch the
thinned corneal apex and cause ulceration:
“Optically, Fick’s ‘Contactbrille’ is based on the same principle as the hydrodiascope
but has the disadvantage that it can be inserted into the eye only with the aid of another
person and acts as a foreign body between the eyelid and eyeball. It may also produce
inflammation in the latter. I state that I have never myself tried out the contact glass
because it seemed too risky to me. Furthermore, this is especially true with keratoconus,
in which the cornea is already markedly bowed forwards. This makes it especially
unpleasant to wear a foreign body in front of the globe.”
“Optisch beruht Fick’s Contactbrille auf demselben Prinzip wie das Hydrodiaskop, hat aber den
Nachtheil, dass sie nur mit Hülfe eines Zweiten angelegt werden kann und dass sie möglicherweise als ein
Fremdkörper zwischen Lid und Bulbus einen Reiz auf den letzteren ausübt. Ich gestehe, dass ich selbst nie
einen Versuch mit dem Contactglas gemacht habe, da mir die Sache zu riskant erschien ; übrigens scheint
es mir gerade bei Keratoconus, wo die Cornea an sich schon stärker vorgewölbt ist, besonders
unangenehm einen Fremdkörper vor dem Bulbus zu tragen.” (11)
Fick himself had tried out his “Contactbrille” only in one isolated case of keratoconus
and the result was not encouraging. Lohnstein believed that a contact lens would not be
tolerated by the eye any longer than a hydrodiascope.
Applications
Lohnstein finished by recommending applications other than the management of
keratoconus for his hydrodiascope:
effecting optical correction of patients with irregular astigmatism would be easier than
the correction of keratoconus and the result would be that much more beneficial because
the cornea had a more regular thickness;
high myopes would profit from the visual correction and the enlargement of the image,
though it was uncertain whether “the appropriate long-term use would arrest the
development of myopia”; (12)
just as Czermak’s orthoscope, were the hydrodiascope to be used as a diagnostic device
in the physician’s office, it could eliminate those corneal irregularities that interfere with
the examination of the ocular media and fundus, thereby facilitating examination of
retinal function. Above all, this could assist in making an early diagnosis in keratoconus
in a situation, for example, where the diagnosis has not been made and a patient’s
symptoms have either been underestimated or attributed to psychological problems.
Within these limitations, the hydrodiascope would usefully replace Czermak’s
orthoscope, which is not waterproof and therefore of limited practical usefulness.
In an addendum that was written in December 1896, in the interval between the
submission of the paper and its publication, Lohnstein returns to the equipping of his
second eye with the hydrodiascope. In this eye, the visual acuity was improved by
combining high-powered cylindrical lenses with the hydrodiascope.
The reaction of ophthalmologists to the publication by this physician, who was not a
specialist in ophthalmology, was quite muted and dwelt on such secondary points as the
poor response of keratoconus to hyperbolic spectacles and Fick’s contact lenses.
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The Era of Hydrodiascopes
1.1.2 - Modifications and Improvements to the Hydrodiascope (1897)
In 1897, a year later, Lohnstein
completed his research with the
publication of a study on the optics of
the corrective lens that needed to be
placed on the front surface of the
hydrodiascope. In this article, entitled
“Die
Berechnung
der
Planconvexlinse des Hydrodiaskops”
(Calculation of the Plano-convex Lens
Figure 14-3
of the Hydrodiascope), we learn that he
Supplement to Lohnstein's publication on his hydrodiascope.
publication: "Die Berechnung der Planconvexlinse des
has effectively pursued his promised Lohnstein's
Hydrodiaskops" (Calculation of the Plano-convex Lens of the
Hydrodiascope) in which he completed his research with the
studies on a new hydrodiascope with
publication of a study on the optics of the corrective lens to be placed
the distance between the front corneal
on the anterior surface of the hydrodiascope.
Th., "Die Berechnung der Planconvexlinse des Hydrodiaskops" Klinische
surface and the front wall of the (LOHNSTEIN
Monatsblätter für Augenheilkunde, 35, 1897, 266-271. - Excerpt page 266)
hydrodiascope reduced to 10.00 mm
and fitted with a lens of 25.00 mm in diameter and a focal length ranging from 26.00 mm
to 35.00 mm. This new model would provide a net enlargement of the visual field with
reduced image magnification of 1.49. Lohnstein indicates that loss of elasticity and
flattening of the rubber border reduces the axial depth of the hydrodiascope by wear and
that mild hypermetropia resulted, although this was easily compensated by
accommodation. In another article, in response to criticism by Fick, Lohnstein mentions
his interest in a hydrodiascope that would be closed off by a plano lens and that would
facilitate ophthalmoscopy:
“The hydrodiascope possesses the advantage of being able to be used with a plano lens
for ophthalmoscopy with an upright image. At maximum, two or three frames of different
sizes at the most would be necessary, as the elastic rubber border easily adapts to the
different shapes of orbital margin. Moreover, at the time of diagnostic examination, it
does not matter much whether the device be hermetically sealed or not because the
patient can lean on the instrument quite firmly during the brief time of examination”
“Das Hydrodiaskop hat den Vorteil, dass es mit einem Planglas in äusserst bequemer Weise zum
Ophthalmoskopieren im aufrechten Bilde verwendet werden kann. Verschiedene Fassungen dürften
höchstens 2 bis 3 benötigt werden, da der elastische Gummirand eine erhebliche Anpassungsfähigkeit an
verschieden geformte Orbitaleingänge besitzt. Ueber dies kommt es bei diagnostischer Verwendung auf
sehr dichten Schluss nicht an, da der Patient selbst während der kurzen Beobachtungszeit den Apparat
ganz fest andrücken kann.” (13)
1.1.3 - The Lohnstein-Fick Controversies (1897)
Lohnstein also entered into a controversy with Fick. This is interesting from a historical
point of view because of the descriptions given by Fick regarding the conduct of his
experiments. (14) The controversy, as documented and following from one issue to the
next, concerned essentially the respective advantages of the hydrodiascope and contact
lens for neutralization of corneal refractive power, correction of corneal anomalies and
the type of solution used for filling the device.
For Lohnstein, an ideal saline solution for use with his hydrodiascope would have a
concentration of 0.85% to 0.90%. Concentrations stronger or weaker caused visual
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The Era of Hydrodiascopes
clouding and the appearance of colored rings around lights, which he attributed to
disturbances in osmotic pressure:
“Some time ago by mistake, I used a sodium chloride solution of only 0.45%. On another
occasion, I used the same solution deliberately for experimental reasons. On each
occasion, I experienced absolutely no burning sensation but rather the feeling of a
peculiar and poorly localized pressure in the front of my eye. Then, an hour later, when
I removed the hydrodiascope, I had a peculiar veil in front of the eye under consideration
that I was easily able to distinguish from the indistinctness of the outside world caused
by my diffusion images. This phenomenon disappeared in about 10 minutes. A flame,
which I was observing during this time, showed weakly defined colored rings. There was
thus true corneal clouding, which, furthermore, could not be objectively detected by one
of my brothers, who was himself a medical doctor, and which, in any event, was minimal.
I drew two conclusions from the experiment I describe: 1) that I am already in a position
to detect very mild diffuse corneal disturbance of the cornea; 2) that such a disturbance
of the corneal epithelium occurs because of water uptake by the corneal epithelium and
consequently can be readily avoided through selection of the correct concentration of the
fluid under consideration.”
“Als ich, einmal aus Versehen und ein anderes Mal experimenti causa, eine NaCl-Lösung von nur 0,45
% benutzte, empfand ich zwar noch kein Brennen, aber das Gefühl einer eigenthümlichen nicht näher zu
lokalisierende Spannung vor dem Bulbus ; als ich das Hydrodiaskop nach einer Stunde absetzte, hatte ich
einen eigenthümlichen Schleier vor dem betreffenden Auge, den ich sehr wohl von der durch meine
Zerstreuungsbilder bewirkten Undeutlichkeit der Aussenwelt zu unterscheiden vermöchte, ein Phaenomen,
das übrigens in etwa 10 Minuten abklang. Eine Flamme, die ich während der Zeit betrachtete, zeigte
schwach angedeutete farbige Ringe. Das war also eine wirkliche Trübung der Hornhaut, die übrigens
objektiv von einem meiner Brüder, einem Mediciner, nicht festgestellt werden konnte, jedenfalls also
minimal war. Ich schliesse aus dem beschriebenen Experiment zweierlei: 1) dass ich schon eine sehr
geringe diffuse Trübung der Hornhaut durch Selbstbeobachtung zu entdecken im Stande wäre; 2) dass eine
solche Trübung durch osmotische Wasseraufnahme seitens der Hornhautepithelien zu Stande kommt,
demnach durch richtige Wahl der Concentration der betreffenden Lösung mit Leichtigkeit vermieden
werden kann.” (15)
In a footnote of the page the journal editor, Zehender, notes:
“Six or seven years ago, the editor of this journal carried out some experiments on the
photography of the human fundus. In order to eliminate the disturbing corneal reflex, he
used a hydrodiascope that was closed off by plano glass. [...] After removal of the device,
the whole cornea appeared completely cloudy, to my not inconsiderable astonishment.
The cloudiness quickly disappeared very shortly afterwards. This could only be
explained as the result of edematous infiltration of the cornea in consequence of contact
with the salt-free water.”
“ Vor etwa 6 oder 8 Jahren hat der Herausgeber dieser Zeitschrift sich mit dem Versuche beschäftigt, den
Hintergrund des menschlichen Auges zu photographieren. Um den störenden Hornhautreflex zu
beseitigen, wurde dabei ein mit physiologischer Kochsalzlösung gefülltes Hydrodiascop mit
planparallelem Abschluss benutzt.[...]. Nach Abnahme des Apparates fand sich zu meinem nicht geringen
Erstaunen die ganze Hornhaut vollständig trübe. Die Trübung verlor sich zwar bald wieder; sie konnte
nicht anders als durch ödematöse Infiltration der Hornhaut in Folge des Contactes mit dem salzlosen
Wasser erklärt werden. “ (16)
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The Era of Hydrodiascopes
1. 2 - The Krakow Binocular Hydrodiascope (1898 - 1899)
About a year later, the idea of using
Lohnstein’s hydrodiascope for the
correction of refractive errors was
taken up again by Majewski, assistant
to
Professor
Wicherkiewicz
Ophthalmology Clinic of the University
of Krakov. Experiments had been
undertaken between March 13, 1898,
and February 5, 1899, and were the
Figure 14-4
subject of a preliminary publication by
Majewski's publication on the binocular hydrodiascope.
Majewski's publication: "Ueber Corrigirende Wirkung des
Majewski at the time of the
Hydrodiaskops Lohnsteins in Fällen von Keratoconus und
inauguration
of
the
new unregelmässigem Astigmatismus" (Concerning the Corrective Effect
of Lohnstein's Hydrodiascope in Keratoconus and Irregular
Ophthalmology Clinic (17). After Astigmatism).
The article describes how the author had connected
two hydrodiascopes together and had thus obtained a form of
completion, the article was published
'spectacles' for binocular correction.
with the title “Ueber corrigirende (MAJEWSKI Casimir Vincenz, "Ueber corrigierende Wirkung des Hydrodiaskops Lohnsteins
in Fällen von Keratoconus und unregelmässigem Astigmatismus", Klinische Monatsblätter
für Augenheilkunde, 37, 1899, 162-167 - Excerpt page 162)
Wirkung
des
Hydrodiaskops
Lohnsteins in Fällen von Keratoconus
und unregelmässigem Astigmatismus” (Concerning the Corrective Effect of Lohnstein’s
Hydrodiascope in Keratoconus and Irregular Astigmatism). The article describes how
the author had connected two hydrodiascopes together and had thus obtained a form of
‘spectacles’ that guaranteed a binocular correction for him. Majewski used “silver alloy
capsules” (Alphablech), an alloy consisting of nickel, copper and zinc that had a white
color reminiscent of silver. The hydrodiascope capsules were fixed to the orbits with
rubber drains of appropriate caliber that he set in a groove at the posterior border of the
device. An adjustable copper thread, with a length determined from the inter-pupillary
diameter, attached the capsules to each other. The choice of the diameter of the drain and
the adjustment of the distance between the two capsules of these “water spectacles”
(Wasserbrille) allowed the device to be fitted to every facial shape:
“I have made use of two capsules made from a thin alloy (Alphablech) for my
experiments. These capsules are joined to each other by means of a flexible copper wire
in such a way that their separation and position relative to each other can be changed
at will. The free border of each metal chamber is provided with a groove, into which one
can press drainage tubing of various calibers. On the temporal side of each chamber,
there is an eyelet through which a small band can be passed and tied behind the head.
In this way, if you select a tube of appropriate size on the one hand and, on the other
hand, bend the connecting wire and tie the small band just the right amount, you can
finally use one and the same ‘Wasserbrille’ (water spectacles) to suit various shapes of
orbit.”
“Ich habe mich bei meinen Experimenten zweier Kapseln aus dünnem Alphablech bedient. Diese Kapseln
sind miteinander mittels eines nachgiebigen Kupferdrahtes verbunden, so dass man ihre Entfernung und
gegenseitige Lage nach Belieben ändern kann. Der freie Rand jeder Blechkammer ist mit einer Rinne
versehen, in welche man Drainröhrchen verschiedenen Kalibers hineinpressen kann. An jeder Kammer ist
schläfenwärts eine Öse angebracht zum Durchführen eines Bändchens, welches am Hinterhaupte
zusammengeschnürt wird. Auf diese Weise, indem man einerseits ein passendes Drainrohr wählt,
anderseits den Verbindungsdraht zwecksmässig einbiegt und endlich das Bändchen mehr oder weniger
stark zusammenschnürt, kann man eine und dieselbe “ Wasserbrille “ verschiedenartig gestalteten
Augenhöhlen anpassen.” (18)
205
The Era of Hydrodiascopes
Majewski arranged to fix a plano-convex lens of +33.00 diopters and 27.00 mm in
diameter to the front wall of the device. An opening in the top allowed instillation of
approximately 15.00 cc of a solution of warm physiological saline. The total visual
correction was obtained by superpositioning additional spectacles with spherical lenses
that also allowed partial concealment of the device:
“In front, every metal alloy chamber has a circular opening (27 mm in diameter) that is
closed off with a strong plano-convex lens (+33.00 D). The device, thus equipped, is then
filled with lukewarm sterilized physiological salt solution through an opening set in the
upper wall. After the device has been filled with water, the subject opens his eyes.”
“Vorn träg jede Blechkammer eine runde Oeffnung (27 mm Durchmesser), welche mit einem starken
planconvexen Glase (+33 D) abgeschlossen ist. Der auf diese Weise angepasste Apparat wird nachher
mittels eines Tropfglases durch eine in obereer Wand angebrachte Oeffnung mit lauwarmer, steriliairter,
physiologischer Kochsalzlösung gefüllt, in welcher der Untersuchte seine Augen öffnet.” (19)
Majewski confirmed the limits of wearing time as described by Lohnstein without
however, providing the actual numerical results for the number of hours achieved. He
described excellent visual results reached in 15 subjects (21 eyes): five with keratoconus,
seven with irregular astigmatism complicated by corneal nebulae, five with unilateral
aphakia and four with high astigmatism. Except for the last-mentioned, not one patient
had been improved by lenses alone using cylindrical, hyperbolic or stenopeic glasses. He
insisted, however, that he had not prescribed hydrodiascopes for everyday use.
In conclusion, Majewski recommended a series of improvements, e.g., by providing the
shell with a plano lens and a groove into which corrective lenses would be slipped.
Lohnstein had already described this idea that Siegrist was to take up again and put into
practice in the years that followed:
“Instead of the powerful plano-convex lens (+33 D), I would recommend closing off the
anterior opening of the device with a plano glass. In the lower half of this opening, a
half-moon-shaped metal groove, in which the requisite plano-convex lens might be
placed, could be connected with its flat surface obviously directed towards the glass
plate. For this purpose, a series of plano-convex lenses (from +20 to +40 D) must be
made available.”
“Statt der starken, planconvexen Linse (+33 D)
möchte ich die vordere Oeffnung des Apparats mit
planparallelen Glasscheiben absperren. Unterhalb
dieser Oeffnung könnte man eine halbmondförmige
Metallrinne anschliessen, in welche das eben
nothwendige planconvexe Glas eingelegt würde,
selbstverständlich mit der flachen Seite dem
Glasscheibschen zugewendet. Zu diesem Zwecke
müsste man über eine Reihe von planconvexen Linsen
(von + 20 D bis + 40 D) verfügen.” (20)
Figure 14-5
Fater's publication concerning the Berne hydrodiascope.
Fater's publication: "Hydrodiaskop und Keratoconus"
(Hydrodiascope and Keratoconus) in which she presents the
retrospective claims of Siegrist's first "water case"
(Wasserkasten) (and new improvements for the
hydrodiascope.
1.3 - The Berne Hydrodiascopes
(1897-1906)
(FATER Sabina, "Hydrodiaskop und Keratokonus", Klinische Monatsblätter für
Augenheilkunde, 44, 1906, 93-109 - Excerpt page 93).
In 1906, Fater, an assistant at the University
206
The Era of Hydrodiascopes
Eye Clinic of Berne, published, at Professor
Siegrist’s urging, a significant paper and a
“Inaugural-Dissertation” describing the
refractive correction of patients with
keratoconus. The title was “Hydrodiascop
und Keratoconus” (Hydrodiascope and
Keratoconus). According to Siegrist’s
retrospective claims, as documented by
Fater, the experiments had commenced after
1897 and would therefore have been
contemporaneous with those of Lohnstein.
1.3.1 - Siegrist’s “Wasserkasten”
(water case) (1897)
In 1897, Siegrist asked the optician Strübin
of Basle (Switzerland), to construct a “water
case” (Wasserkasten) that was inspired by
Czermak’s orthoscope for a young male
patient with bilateral keratoconus. At this
time, Siegrist was not aware of Lohnstein’s
publication and also ignored the papers of
other earlier authors, notably those of Hasner
(1851) and Gerloff (1891).
Figure 14-6
Fater's "Inaugural -Dissertation" concerning the Berne
hydrodiascope.
Front page of Fater's "Inaugural-Dissertation" for M.D.:
"Hydrodiaskop und Keratoconus" (Hydrodiascope and
Keratoconus) in which she presents the retrospective claims
of Siegrist's first "water case" (Wasserkasten) (and new
improvements for the hydrodiascope.
(FATER Sabina, Hydrodiascop und Keratoconus, Inaugural-Dissertation Fakultät
Bern, Hoffmann, Stuttgart, 1906)
For the construction of the device, Siegrist
provided Strübin with a plaster mold of the
orbito-nasal region. The water-tight case had
a depth of 15.00 mm, the distance from the
front surface of cornea to the anterior wall of
the device, and it was fitted outside the
orbital margin with a strip of rubber. Its
anterior wall was pierced by an orifice in
front of which a convex lens of high power
was mounted. This device was destined to
permit a useful but very transient
improvement in the patient’s visual acuity.
1.3.2 - Siegrist’s Hydrodiascopes
(1898).
By the time at which the construction of the
device was complete, Siegrist was aware of
Lohnstein’s publication. He arranged for
Sydow of Berlin to deliver an original
hydrodiascope, which was worn by the
patient from March 1898 and which was
better tolerated and produced a significantly
better visual result than the earlier model.
The Berlin hydrodiascope was equipped with
Figure 14-7
The prototype of the Berne hydrodiascope (1897).
Lateral and front views of the "water case" (Wasserkasten)
constructed for Siegrist by Struebin, an optician in Basle.
Modeled on Czermak's orthoscope, this container was
applied outside the orbital rim to the face, thus explaining its
broad dimensions:
30.00 mm in vertical diameter.
40.00 mm in horizontal diameter.
A 20.00-mm diameter plano convex lens is mounted on the
front surface.
(FATER Sabina, "Hydrodiaskop und Keratokonus", Klinische Monatsblätter für
Augenheilkunde, 44, 1906, 93-109 - Figure 1 page 94).
207
The Era of Hydrodiascopes
a +26.00 diopter lens. This could be
supplemented by glasses for near vision and
could be worn for up to eight hours per day,
notwithstanding
the
disconcerting
appearance that exposed the patient to jests
from his fellow workers. Fater provided
great detail regarding the history of this
patient, a bank employee for whom
successes alternated with failures up to the
time of his suicide by hanging:
Figure 14-8
The first model of the Berne hydrodiascope.
Earliest version of Siegrist's modified hydrodiascope
constructed by the Bischhausen Brothers, opticians in Berne.
After taking into account Lohnstein's and Majewski's data,
Siegrist reduced the size to 25.00 mm in vertical diameter
and 35.00 mm in horizontal diameter. The front side is shut
by a 15.00-mm plano glass, anterior to which a screw system
allows a corrective plano-convex lens to be fixed to it.
(FATER Sabina, "Hydrodiaskop und Keratokonus" Klinische Monatsblätter für
Augenheilkunde, 44, 1906, 93-109 - Figure 2 page 96).
Figure 14-9
The second model of the Berne hydrodiascope.
Second version of Siegrist's modified hydrodiascope
constructed by the Bischhausen Brothers, opticians in Berne.
The dimensions remain unchanged relative to the previous
model. The plano-convex lens is placed in a slide, allowing
easier exchange and adaptation for far and near vision.
(FATER Sabina, "Hydrodiaskop und Keratokonus" Klinische Monatsblätter für
Augenheilkunde, 44, 1906, 93-109 - Figure 3 page 97).
“The patient was so extraordinarily happy
with his hydrodiascope that, without asking
Professor Siegrist’s advice, he became a
bank employee where he carried out written
assignments with the help of his
‘Wasserkasten’ (water case) 6-8 hours a day.
Unfortunately, his previous state of
depression could not be completely
eliminated, this probably being exacerbated
by the mocking of his female fellow worker,
which the patient had to put up with on
account of his odd-looking glasses. When,
about six months later, as the result of a
misunderstanding, he came to believe that
his younger brother had passed away in
another country, he committed suicide by
hanging himself.”
Patient war nun mit seinem Hydrodiaskop so
ausserordentlich zufrieden, dass er, ohne Prof.
Siegrist weiter zu fragen, als Angestellter in ein
Bankgeschäft eintrat und dort täglich 6-8 Stunden
schriftliche Arbeiten mit Hilfe seines Wasserkastens
verrichtete. Leider konnte die einmal ausgebrochene
Melancholie, welche noch neue Nahrung durch den
Spott erhielt, welchen der Patient von seiner jüngeren
Mitangestellten ob seiner eigentümlichen Brille zu
ertragen hatte, nicht völlig gebannt werden. Als
Patient ein halbes Jahr später aus Missverständnis
glaubte, sein jüngerer Bruder sei im Ausland
gestorben, machte er seinem Leben durch Erhängen
ein Ende.” (21)
The modifications in the hydrodiascope that were proposed by Lohnstein and Majewski
led the way to perfecting a new generation of hydrodiascopes that were manufactured by
the Berne opticians the Bischhausen Brothers. This device was closer to the eye, rested
on the periphery of the eyelids and was equipped with a lens of smaller diameter. The
lenses of the first models were fixed by a screw in front of a glass plate and could
therefore be changed if necessary. In subsequent models, the corrective lens was able to
slide within a groove, which made it both removable and interchangeable:
“To this end, plano glass only was riveted in the front wall of the device, onto which any
208
The Era of Hydrodiascopes
desired strong plano-convex lens could be screwed in on its plano side, or, as in
Professor Siegrist’s most recent modification of the hydrodiascope, could be set in a type
of spectacle frame. It was thus also possible to unscrew a second convex lens positioned
in front for close work and to replace it with little difficulty through an increase in power
of the first plano-convex lens.”
“Zu diesem Zwecke wurde in die vordere Wand des Apparates nur ein Planglas eingenietet, auf welches
nun mittelbar ein beliebiges starkes Plankonvexglas mit seiner planen Seite aufgeschraubt oder wie in der
neuesten Modifikation des Hydrodiaskopes von Prof. Siegrist ähnlich wie in ein Brillengestell aufgesetzt
werden konnte. Auf diese Weise wurde es auch möglich, dass bei der Nahearbeit vorzusetzende zweite
Konvexglas auszuschalten und dasselbe nun einfach ohne viel Mühe durch eine Verstärkung des ersten
Plankonvexglases zu ersetzen.” (22)
In the interface between the plate glass and the lens, diaphragms of various diameters
could be interposed. The esthetic appearance of the device was improved by removing
the filling pipes. The method of application was simplified: the liquid was poured
directly into the hydrodiascope that was held horizontally, and then the eyes were
submerged into the liquid before fixing the device at the occiput.
1.3.3 - Fater’s Observations (1906)
The case reports described by Fater show considerable improvement in the visual
acuities of patients affected by late-stage keratoconus, which was previously considered
to be incurable. Fater deals at length with those questions that seemed to her to be
fundamental for these devices, such as the composition of the liquid used for filling,
image enlargement, and disturbances of accommodation.
The filling solution that was best tolerated and the one most popular at Berne was
Ringer’s solution (23). A 13.90% physiological saline solution, equivalent to tears, was
intolerable in its sensation compared with saline solutions of 7.50% and 8.80%.
The enlargement of the retinal image due to the magnifying loupe effect resulting from
the lengthening of the optical system was appreciated, studied and explained both for
patients affected by keratoconus and for healthy persons who had tried out the
hydrodiascope.
Lohnstein had previously described paresis or even apparent paralysis of
accommodation while using the hydrodiascope. Fater confirmed the variable presence
of accommodation, depending on age. The experiments, those carried out both on
healthy persons (essentially physicians at the clinic) and on actual patients did not supply
any consistent conclusions that would explain this phenomenon. It seemed, nevertheless,
that accommodation was essentially lost with the deepest hydrodiascopes, the lenses of
which were furthest from the eye, and that the phenomenon varied proportionally with
the length of the optical system (24).
The inevitable comparison of the hydrodiascopes with the “Fick-Sulzer contact shells”
(this was how Siegrist referred to them at the time) was significantly in favor of the
hydrodiascopes. This was because they could be worn for six to eight hours a day
without ocular problems and always brought visual acuity back to normal. The patients
tolerated the esthetic unsightliness of these devices because of the visual improvement
that it gave them.
209
The Era of Hydrodiascopes
Fater concluded that the use of the hydrodiascope with improvements by Siegrist was
really indicated for the correction of keratoconus. The modifications contributed by the
Berne Clinic, especially the possibility of intercalating black paper diaphragms between
the plano glass and the plano-convex lens also made it a useful device for research
purposes:
“Based on the studies we performed, we can strongly recommend Lohnstein’s
hydrodiascope. This is, as you know, Majewski’s modification both for the management
of keratoconus and especially for measuring the range of accommodation in eyes
affected by keratoconus. With an iris diaphragm consisting of black paper that can be
interposed between the plate glass and plano-convex lens, as recommended in Professor
Siegrist’s modification, the hydrodiascope represents a device that will certainly find
application even in the most diverse of experimental studies.”
“Wir können also, gestützt auf die angeführten Untersuchungen, das Lohnsteinsche Hydrodiaskop, das ja
eine Modifikation durch Majewski erfahren hat, sehr zur Behandlung des Keratokonus und speziell zur
Bestimmung der Akkommodationsbreite bei Keratokonusaugen empfehlen. In der von Prof. Siegrist
angegebenen Modifikation mit einschaltbaren Irisblenden aus schwarzem Papier zwischen Planglas und
Plankonvexglas stellt das Hydrodiaskop einen Apparat dar, der sicherlich zu den verschiedensten
experimentellen Untersuchungen noch wird Verwendung finden.” (25)
1.4 – Other Hydrodiascope Users
Year
1908
1909
1909
1909
1909
1909
1909
1923
Publication
Lorenz (Leipzig) "Ueber Keratokonus" (Concerning Keratokonus)
Terson (Paris) : "Note sur la Pathogénie et le Traitement du Kératocône" (Note on
the Pathogenesis and the Treatment of Keratoconus)
Lauber (Vienna): "Randatrophie der Kornea mit hochgradiger Kerectasia
peripherica" (Marginal Corneal Atrophy with Advanced Peripheral Corneal
Ectasia)
Uthoff (Breslau): "Ueber einen Fall von Keratokonus mit Sektionsbefund"
(Concerning a Case of Keratokonus with Histopathologic Examination)
Parisotti (Rome) : "Le Kératocône" (Keratoconus)
Antonelli (Naples) : "Quelques Remarques sur le Traitement Optique du
Kératocône" (Several Comments on the Optical Treatment of Keratoconus)
Wicherkiewicz (Krakow): "Discussion" on Parisotti's report
Lauber & Kraemer (Vienna): "Ueber die Maßnahme gegen Keratokonus mit
besonderer Berücksichtigung der optischen Hilfsmittel, spez. der Hyperbolischen
Gläser" (Concerning the Measures against Keratoconus with Particular Emphasis
on Optical Means of Treatment, notably Hyperbolic Glasses)
Table 14 - 2
Publications by hydrodiascope users (1908-1923).
After the landmark studies by Siegrist, the hydrodiascope had acquired “city rights” in
ophthalmological practice, and other authors used it sporadically with more or less
conviction and success even outside of German-speaking circles.
1.4.1 - Helmbold (1906 / 1913)
In 1913, Rudolf Helmbold, an ophthalmologist from Danzig (Germany), reports how a
trial experiment was carried out at the Koenigsberg Eye Clinic in a patient affected by
keratoconus. Helmbold demonstrated better visual acuity with the hydrodiascope than
with spectacles equipped with stenopeic holes. (26)
210
The Era of Hydrodiascopes
1.4.2 - Lorenz (1908)
Case
1 (Lorenz) Self-observation
2
3
4
5
Spectacle
OD
5/6
Counts Fingers at 3 meters
Counts Fingers at 3 meters
6/125
6/24
Correction
OS
6/12
6/24
6/36
6/125
6/125
Hydrodiascope
OD
6/5
6/12
6/6
6/6
6/9
Correction
OS
6/5
6/5
6/9
6/6
6/9
Table 14 - 3
Visual Improvement obtained with the hydrodiascope (Maria Lorenz, Inaugural Dissertation Leipzig, 1908)
On the April 30, 1908, Maria Lorenz
presented her “Inaugural Dissertation”
entitled “Ueber den Keratoconus”
(Concerning Keratoconus) to the Faculty of
Medicine in Leipzig. She did this on the
initiative of Professor Sattler. She herself
suffered from the same condition
(keratoconus) and she noted improvement in
her vision with the hydrodiascope. In her
study, she emphasizes the need for the
corrective lenses slipped in the front the
instrument to be well centered. Lorenz
describes the loss of accommodation due to
the effect of the hydrodiascope. In her
experience and in the experience of other
patients, Ringer solution is better tolerated
than 0.75% and 0.88% saline.
Lorenz concluded that, if there were no other
alternative, the hydrodiascope constituted an
excellent means for the optical correction of
keratoconus:
Figure 14-10
Title Page of Inaugural Dissertation "Ueber den
Keratoconus" (Concerning Keratoconus) by Maria Lorenz
(1908)
In April 1908, Maria Lorenz, herself afflicted with
keratoconus, defended her "Inaugural dissertation" to the
Faculty of Medicine in Leipzig. In her dissertation, she
describes the optical correction of this condition by the
hydrodiascope.
“From the experience acquired on my own
eyes with the hydrodiascope and in eyes
affected by keratoconus that I have
den Keratoconus, Inaugural-Dissertation Fakultät
examined, it appears that there exists here an (LORENZ Maria, Ueber
Leipzig, B. Georgi, Leipzig, 1908)
exceptionally suitable means for correcting
keratoconus. Furthermore, the literature
shows that there is no means other than the hydrodiascope to improve visual acuity in
such an impressive manner or even to correct it completely. The hydrodiascope that I
used has a depth of 1.5 cm, which is significantly too deep, and I think that if the
customary depth of 1 cm could be further diminished, accommodation would be
improved.”
“Aus den an meinen eigenen Augen und an den übrigen von mir geprüften Keratoconusaugen mit dem
Hydrodiaskop gemachten Erfahrungen erscheint mit dieses als ein außerordentlich gutes
Korrektionsmittel für den Keratoconus, und aus der Literatur ist ersichtlich, dass es kein zweites Mittel
gibt, das die Sehschärfe in dem Masse verbessert, oder sogar vollkommen korrigiert, wie es eben das
Hydrodisakop tut. Das von mir benutzte Hydrodiaskop besitzt eine Tiefe von 1,5 cm, das ist entschieden
zu tief, und ich glaube auch, dass sich die sonst übliche Tiefe von 1 cm noch verringern ließe.” (27)
211
The Era of Hydrodiascopes
1.4.3 - Terson (1909)
In 1909, Terson, a French ophthalmologist, makes no reference to any personal
experience with hydrodiascope, but in a “Note sur la Pathogénie et le Traitement du
Kératocône” (Note on the Pathogenesis and Treatment of Keratoconus) he mentions:
“Contact lenses and the hydrodiascope are prostheses to be tried systematically.” (28)
1.4.4 - Lauber (1909)
On May 12, 1909, H. Lauber presented a male patient at the Vienna Ophthalmological
Society, whose hydrodiascope improved the visual acuity of an eye affected by advanced
peripheral corneal ectasia and marginal corneal ectasia associated with pronounced
myopia:
“Lauber presented a 64-year-old male with bilateral peripheral corneal atrophy and
advanced peripheral corneal ectasia. The consequence of this condition was myopic
astigmatism of high degree with reduction of visual acuity to 1/80. However, using the
hydrodiascope produced a 2/3 rise in visual acuity.”
“Lauber stellt einen 64 jährigen Mann vor mit beiderseitiger Randatrophie der Kornea und hochgradiger
Keratectasia peripherica. Die Folge davon war ein hochgradiger myopischer Astigmatismus mit
Herabsetzung der Sehschärfe auf 1/80. Mit dem Hydrodiaskop jedoch liess sich die Sehschärfe auf 2/3
heben.” (29)
1.4.5 - Uhthoff (1909)
In 1909, in an article entitled “Ueber einen Fall von Keratokonus mit Sektionsbefund”
(Concerning a Case of Keratoconus with Histopathological Examination), Uhthoff, of
the University Eye Clinic of Breslau, Germany, presented corneal histopathology in a
patient from whom this tissue had been excised by reason of keratoconus. He included
some more general comments on the correction of keratoconus with the clinical history
of the patient. He expressed his disappointment with the glass-blown contact shells of
the Müller Brothers of Wiesbaden, described his interest in stenopeic glasses, and
expressed surprise at the visual improvement right up to normal vision obtained with a
hydrodiascope. Patients were able to wear the device for several hours when they used
Ringer’s solution. In spite of that, the hydrodiascope was useful only for short periods
and in a single eye:
“A proportion of the cases showed a surprisingly great improvement in visual acuity (of
up to a visual acuity of 1) as the result of the application of Lohnstein’s hydrodiascope.
Furthermore, the correction was relatively well tolerated for hours at a time because of
the employment of Ringer’s solution. And, yet, this accessory device can be considered
usable only for short periods of time. Besides, we have in our possession up to this time
no practically useful hydrodiascope such as could be used for both eyes simultaneously
in the same way as a pair of spectacles. In unilateral keratoconus, with a healthy second
eye, the correction of the cone does not have any great importance. If, however, the
patient is dependent on only one eye only and that eye is affected by keratoconus, then
this method of treatment can occasionally render great service.”
“Ueberraschend war in einem Teil der Fälle die Verbesserung der Sehschärfe (bis zu S = 1) durch
Verwendung des Lohnsteinschen Hydrodiaskops, auch wurde unter Verwendung der Ringerschen Lösung
212
The Era of Hydrodiascopes
diese Korrektion stundenlang vom Auge relativ gut vertragen, doch kann dieses Hilfsmittel auch nur als
temporär benützbares angesehen werden. Übrigens besitzen wir bisher keine praktische verwendbare
derartige hydrodiaskopische Vorrichtung für beide Augen gleichzeitig, welche etwa im Sinne einer Brille
benützt werden könnte; Bei einseitigem Keratokonus aber und bei gesundem zweiten Auge hat die
Konuskorrektion keine grosse Bedeutung; ist aber ein Kranker lediglich auf ein Auge mit konischer
Hornhaut angewiesen, so kann ihm gelegentlich mit dieser Methode ein grosser Dienst geleistet werden.”
(30)
1.4.6 - Parisotti (1909)
In 1909, Parisotti, Professor of Ophthalmology in Rome (Italy), was commissioned to
present the annual report to the French Society of Ophthalmology on the subject “Le
Kératocône” (The Keratoconus). Parisotti noted that the hydrodiascope allowed
effective optical correction of patients with keratoconus but that the device still had to
be perfected, towards which end “clinicians in Germany and Switzerland were currently
striving”. His presentation is a collection of stereotypes without relationship to historical
facts.
“In a more recent times, Lohnstein has recommended a contact lens with interposition
of liquid, which he has named hydrodioscope [sic]. He described his device in the
December 1896 issue of the Klinische Monatsblätter für Augenheilkunde. He conceived
it for a case of irregular astigmatism. But it is very easy to understand that he has ended
up using it for keratoconus. […]. In order to achieve this goal, Lohnstein uses his device
to surround the whole anterior portion of the eye with liquid and replaces the static
corneal and anterior chamber refraction with a plano-convex lens consisting of the
anterior surface of the liquid chamber of the device. […]
This spectacle is worn like any ordinary spectacle, by means of a ribbon tied behind the
head and a rubber border that adapts perfectly to the orbital margins and prevents the
loss of liquid. The lukewarm liquid is poured into the device through a small filling tube.
[…]. The need for further improvements is quite apparent because it is clearly the most
rational approach that has been conceived up to the present time. The advantages that
Majewski and other clinicians in Germany and Switzerland recognized in this approach
need not surprise us. Miss Sabine Jater [sic], from Odessa, has suggested an
improvement in the construction of the hydrodiascope.”
“A une époque encore plus récente, Lohnstein a conseillé un verre de contact avec interposition du liquide
qu’il a appelé hydrodioscope (sic). Il a décrit son appareil dans le numéro de décembre 1896 du Klinische
Monatsblätter für Augenheilkunde. Il l’a imaginé à vrai dire pour un cas d’astigmatisme irrégulier. Mais
il est bien facile de comprendre qu’il en soit venu à l’utiliser pour le kératocône. […]. Pour atteindre ce
but, Lohnstein entoure de liquide au moyen de son appareil toute la partie antérieure de l’œil, et remplace
la réfraction statique de la cornée et de la chambre antérieure par un verre plan-convexe qui forme la face
antérieure de sa chambre à liquide.
Cette lunette se porte comme une lunette ordinaire, par un ruban qui se noue derrière la tête, et un rebord
en caoutchouc s’adaptant parfaitement aux bords orbitaires, de manière à empêcher la sortie du liquide.
Celui-ci est versé tiède dans un petit tube d’introduction. […] Le besoin de perfectionnements nouveaux
se fait grandement sentir, car il est certain que c’est là le moyen le plus rationnel qu’on ait imaginé
jusqu’à présent ; les avantages que lui reconnaissent Majewski et d’autres cliniciens de l’Allemagne et de
la Suisse ne doivent pas nous étonner. Mlle Sabine Jater (sic), d’Odessa, a proposé une amélioration dans
la construction de l’hydrodioscope.” (31)
From the 23 contributors to the discussions that followed this presentation, only two
expressed an opinion on the hydrodiascope, Antonelli and Wicherkiewicz
213
The Era of Hydrodiascopes
1.4.7 - Antonelli (1909)
At the time of the discussion of Parisotti’s report, Antonelli gave a paper describing the
last model of the Berne hydrodiascope in which he documented its faults: its lack of
cleanliness, its deficient water-tightness, the escape of liquid through the lacrimal
passages and the blurriness of the vision. He concluded that, unlike Sulzer’s contact
lenses, the hydrodiascope had reached a stage of development beyond which it could not
be perfected and that patient acceptance was problematical. In the same year, he
published his own contribution under the title “Quelques remarques sur le traitement
optique du kératocône” (Several Comments on the Optical Treatment of Keratoconus):
“I have demonstrated in the course of the observation reported a moment ago how useful
contact lenses can be, in that they are perfectly tolerated and give absolutely normal
visual acuity back to the patient. I would not be able to say as much for Lohnstein’s
hydrodiascope. Thanks to the cooperation of the manufacturers (the Bischhausen
brothers, Opticians in Berne), I was able to demonstrate Siegrist’s modified instrument
before the Congress, such as is described in the thesis of his pupil, Miss Sabine Fater. I
have tried it out a sufficient number of times to be able to say that I feel a certain
repugnance to sticking the eye into a liquid-filled device that is difficult to clean
satisfactorily and of which the water-tightness is necessarily imperfect. Furthermore, the
movements of the facial muscles are sufficient to disrupt the water-tightness and to allow
the liquid to run down the cheek and, unless there is obstruction of the lacrimal system,
this eyebath causes a flow of fluid down the nose that is most disturbing. Finally, the
considerable distance between the plano-convex lens and the retinal screen makes the
point of sharpest focus particularly delicate and variable. […] It is sufficient to state the
opinion that the hydrodiascope will be difficult to accept as a veritable means of
managing patients suffering from keratoconus and that, following the same logical
development of ideas, one can claim for contact lenses only a really practical
application.”
“J’ai montré au cours de l’observation rapportée tout à l’heure, combien les verres de contact peuvent
être utiles, étant parfaitement supportés et redonnant une vision absolument normale. Je ne saurais en dire
autant de l’hydrodiascope de Lohnstein. Grâce à l’obligeance des constructeurs, les frères Bischhausen,
opticiens à Berne, j’ai pu montrer au Congrès le modèle de l’instrument modifié par Siegrist, tel qu’il est
décrit dans la thèse de Mlle Sabine Fater, son élève. Je l’ai suffisamment essayé, pour pouvoir dire qu’il
y a une certaine répugnance à plonger son œil dans un liquide qui baigne un objet difficile à nettoyer
idéalement; que l’étanchéité ne peut pas être parfaite, et, du reste, les mouvements des muscles de la face
suffisent à la troubler et à laisser couler le liquide sur la joue; qu’à moins d’obstruction lacrymale, ce
bain oculaire donne un écoulement nasal des plus gênant ; qu’enfin la distance considérable entre le verre
plan-convexe et l’écran rétinien rend la mise au point particulièrement délicate et variable. […] C’est
assez pour affirmer que l’hydrodiascope sera difficilement accepté comme un véritable moyen de
soulagement pour les malades de kératocône, et que, dans le même ordre d’idées, seuls les verres de
contact peuvent prétendre à une application vraiment pratique.” (32)
1.4.8 - Wicherkiewicz (1909)
Wicherkiewicz recalled finally that after 1898 the hydrodiascope had produced
significant improvements in visual acuity in the hands of his former assistant, Majewski:
“Lohnstein’s hydrodiascope as perfected by my former assistant, Professor Majewski,
considerably improves the visual acuity up to 6/10 or even 8/10.” (33)
214
The Era of Hydrodiascopes
1.4.9 - Lauber - Krämer (1923)
Many years later, in June 1923, the hydrodiascope was recalled once again to mind by
two Viennese ophthalmologists, Krämer and Lauber, during a discussion at the Viennese
Ophthalmological Society. The former strongly recommended the return to hyperbolic
spectacle lenses, the manufacture of which had been discontinued, whereas Lauber made
the comment “that he recommended the hydrodiascope above all to demonstrate to
patients how much could be achieved by appropriate therapy for this eye disease”. This
recommendation caused Krämer to express the following reservations: “It seems risky
to me to wish to demonstrate to the patient by means of the hydrodiascope how well he
is going to see after the operation because the results of the operation were far from
being satisfactory and the fact that the numerous failures were usually not published in
the literature”. (34)
1.4.10 - Krämer (1923)
Some time after that, Krämer published his lecture entitled: “Über die Maânahme gegen
Keratokonus mit besonderer Berücksichtigung der optischen Hilfsmittel, spez. der
hyperbolischen Gläser” (Concerning the measures against keratoconus with particular
emphasis on optical means of treatment, notably hyperbolic glasses). In his plea for
hyperbolic spectacle glasses, Krämer gave a glowing description of the favorable results
obtained with the hydrodiascope:
“We have already seen that no other method can measure up to the hydrodiascope, as
far as optical effectiveness is concerned. This water chamber, placed in front of the eye,
completely eliminated corneal refractive power while producing ‘an underwater eye’
and was applied by Lohnstein for his own use in the year 1896. It was also invented
independently by Siegrist a year later. […] Unfortunately, because of its impossible
shape, the use of this wonderful device is limited to the ‘charity room,’ and only in
desperate situations will a patient come to the point of using it on himself in public.“
“Wir haben schon erkannt, daâ sich kein anderes Mittel an optischer Wirksamkeit mit dem Hydrodiaskop
messen kann. Dieser vor das Auge zu setzende Wasserkasten, der die Hornhautrefraktion vollständig
ausschaltet, indem er ein « Auge unter Wasser » erzeugt, wurde im Jahre 1896 von Lohnstein zu eigenem
Gebrauch ersonnen, ein Jahr später von Siegrist selbständig gefunden. […]. Leider bleibt aber dieses
glänzende Hilfsmittel wegen seiner unmöglichen Form auf die Arbeit in camera caritatis beschränkt und
nur in ganz verzweifelten Fällen wird ein Kranker dahin zu bringen sein, sich seiner öffentlich zu
bedienen.” (35)
1. 5 – The Hydrodiascope: a Bygone Evolutionary Step in the
Optical Correction of Keratoconus
Year
1916
1917
Publication
Siegrist (Berne) "Die Behandlung des Keratokonus" (The Treatment of Keratoconus)
Lüdemann (Berne) "Hydrodiaskop oder Kontaktglas zur Korrektur des Keratokonus"
(Hydrodiascope or Contact Glass for the Correction of Keratoconus)
Table 14 - 4
Last publications on hydrodiascopes (1916-1917).
215
The Era of Hydrodiascopes
1.5.1 - Siegrist (1916)
(Figures 14 – 11 & 14 - 12)
In 1916, Siegrist provided a new
and comprehensive account of the
modern treatment of keratoconus
under the title “Die Behandlung
des Keratokonus” (The Treatment
of Keratoconus). In his 21-page
article, he reviews the theoretical
arguments regarding the etiology of
the trophic corneal defects
responsible for keratoconus and
enumerates the various optical
Figure 14-11
methods for correcting keratoconus
Illustration describing the esthetic superiority of the Müller brothers'
available at the time:
blown contact shells with respect to the hydrodiascope.
Patient suffering from keratoconus.
hyperbolic and conical lenses that
On the right: with Siegrist hydrodiascope.
On the left: with a blown Müller Brother's contact shell (worn in the right were practically useless for visual
eye).
improvement in the cases studied,
(SIEGRIST August, "Die Behandlung des Keratokonus", Klinische Monatsblätter für
Augenheilkunde, 56, 1916, 400-421 - Figure 8 & 9 of pages 414 & 415).
the blown contact lenses used by
Fick, as well as the ground contact
lenses used by August Müller and Sulzer, but
which no optician is able to produce on a large
scale,
finally, the hydrodiascopes, regarding which
he quotes Lohnstein’s publications and also
those of Majewski and Fater, the latter being
directly inspired by her own studies at the
Berne Eye Clinic.
It turns out that the improved Berne
hydrodiascope easily normalizes the visual
acuity of nearly all patients affected by
keratoconus. It can be worn without exception
for 6 to 8 hours a day without producing
lesions or significant ocular symptoms. The
unsightly appearance of the patient is the main
disadvantage, which, however, is tolerated
with difficulty and resignation in the absence
of any therapeutic alternative:
Figure 14-12
Title Page of Inaugural Dissertation "Hydrodiaskop oder
Kontaktglas zur Korrektur des Keratokonus"
(Hydrodiascope or Contact Glass for the Correction of
Keratoconus). by Anni Lüdemann (1917).
In his "Inaugural-Dissertation", Anni Lüdemann published
the results of an experimental comparison of successive
fitting of a hydrodiascope and a Müller Brothers contact
shell in ten patients with keratoconus.
(LÜDEMANN Anni, Hydrodiaskop oder Kontaktglas zur Korrektur des
Keratokonus, Inaugural-Dissertation Fakultät Bern, S. Karger, Berlin 1917).
216
“Like Lohnstein, I too discovered that the
visual acuity of nearly all keratoconus
patients can be easily raised to normal
through the use of this water case. […] It has
also been demonstrated that these
hydrodiascopes can easily be worn for 6 to 8
hours using physiological saline solution or
Ringer solution without damage to or
inflammatory reactions in the ocular globe.
Ringer’s solution proved itself to be the best.”
The Era of Hydrodiascopes
“Wie Lohnstein, so fand auch ich, dass durch diesen Wasserkasten die Sehschärfe fast aller
Keratokonuspatienten ohne Schwierigkeit zur Norm erhöht werden kann. […]. Es hat sich auch gezeigt,
dass diese Hydrodiaskope mit physiologischer Kochsalzlösung oder mit Ringerscher Lösung mit
Leichtigkeit 6-8 Stunden getragen werden können ohne Schädigung oder Reizungen des Augapfels. Am
besten hat sich die Ringersche Lösung bewährt.“ (36)
And further on:
“It cannot be denied that the hydrodiascope possesses a great advantage when
compared with the Fick-Sulzer contact glasses, namely the advantage that this device
can be worn without exception for 6-8 hours daily without lesions or significant
disturbance to the eye and that it almost always brings grossly reduced visual acuity
back to normal. The major disadvantage of the hydrodiascope lies in the disfigurement
of its wearer. If one considers that there is no other means for a patient with bilateral
keratoconus to raise his reduced visual acuity significantly, one has to conclude that the
majority of keratoconus patients accept the price of this disadvantage but with no
pleasure and a heavy heart.”
“Es ist nicht zu leugnen, dass das Hydrodiaskop im Gegensatz zu den Fick-Sulzerschen Kontaktgläsern
einen grossen Vorteil aufweist, nämlich den Vorteil, dass dieser Apparat ausnahmslos nach einer gewissen
Uebung täglich 6-8 Stunden ohne Schädigung oder wesentliche Belästigung des Auges getragen werden
kann und dass er fast immer die hochgradig verminderte Sehschärfe zur Norm zurückführt. Der
Hauptnachteil des Hydrodiaskops beruht in der Entstellung seines Trägers. Wenn man bedenkt, dass es für
einen beidseitigen Keratokonuspatienten kein anderes Mittel gibt, seine meist stark verminderte Sehkraft
wesentlich zu heben, so begreift man, dass dieser Nachteil von den meisten Keratokonuspatienten, wenn
auch ungern und mit schwerem Herzen, in den Kauf genommen wird.” (37)
However, for a short time, Siegrist used the glass-blown contact shells, namely the
“Kontaktadhäsionsbrille” (adhesion-contact-spectacles) (38) of the ocularists Müller
Brothers of Wiesbaden. These were significantly superior to ground contact lenses of
Sulzer. The experiments with these new contact lenses, described in detail by Siegrist,
gave such conclusive results, as much by their good toleration as by their duration of
wearing time reaching 9 to 10 hours, that it was necessary to admit that the
hydrodiascope epoch was definitely a thing of the past:
“I am convinced that these modern
contact glasses will make the
hydrodiascope totally unimportant and
dispensable, as it represents only one step
in our attempts to perfect our optical
devices against keratoconus.”
“Diese moderne Kontaktgläser werden nach
meiner Ueberzeugung das Hydrodiaskop, welches
nur eine Stufe in der Vervollkommungsbestrebung
unserer optischen Hilfsmittel gegen Keratokonus
darstellt, vollkommen unnötig und entbehrlich
machen.” (39)
1.5.2 - Lüdemann (1917)
In 1917, the following year, the matter
was again revisited, this time by
Figure 14-13
Publication of a comparison between the hydrodiascope and the
Müller Brothers' contact shells.
In this study entitled "Hydrodiaskop oder Kontaktglas zur
Korrektur des Keratokonus" (Hydrodiascope or Contact Glass for
the Correction of Keratoconus Anni Ludeman, of the Berne Eye
Clinic published the results of an experimental comparison of
successive fitting of a hydrodiascope and a Müller Brothers
contact shell in ten patients with keratoconus.
(LÜDEMANN Anni, "Hydrodiaskop oder Kontaktglas zur Korrektur des Keratokonus",
Zeitschrift für Augenheilkunde, 56, 1917, 267-289. - Excerpt of page 267).
217
The Era of Hydrodiascopes
Lüdemann, Siegrist’s first assistant at the Berne Eye Clinic, under the title
“Hydrodiaskop oder Kontaktglas zur Korrektur des Keratokonus” (Hydrodiascope or
Contact Glass for the Correction of Keratoconus). In this new study, as “InauguralDissertation” and as a journal article, the Berne Clinic assistant published the results of
an experimental comparison of the successive fitting of these devices, hydrodiascope
and contact lens, in ten keratoconus patients.
According to this article, the hydrodiascopes had the advantage of excellent optical
correction and all the patients achieved 20/20 or better. The magnifying loupe effect
causing enlargement of the images was often an appreciable advantage:
“The principal advantage of the hydrodiascope is […] the excellent correction of the
refractive error and the resultant normalization of visual acuity. This result can be
achieved only by using the hydrodiascope to place in position without difficulty a
spherical non- astigmatic cornea of precisely the correct power.”
“Der Hauptvorteil des Hydrodiaskopes ist, [...] die vorzügliche Korrektur des optischen Fehlers und die
hierdurch erzielte Normalisierung der Sehschärfe. Dieses Resultat kann nur dadurch erreicht werden, daâ
es eben beim Hydrodiaskop möglich ist, eine sphärische nicht astigmatische Hornhaut von ganz beliebiger
Brechkraft ohne Schwierigkeiten einzusetzen.” (40)
The major disadvantages of the hydrodiascopes were the necessity of large quantities of
saline solution for positioning them and the unsightliness that wearing them entailed.
Even if this imposition was reduced with later models, it constituted a handicap for
social life. Finally, certain patients complained of disturbances of accommodation:
“The disadvantages of the hydrodiascope are not insignificant. Above all, the
positioning of the hydrodiascope always requires a certain quantity of saline solution,
besides significantly disfiguring the person concerned much more than all other
spectacle glasses. Thirdly, accommodative power is much impaired by wearing the
hydrodiascope.”
“Die Nachteile des Hydrodiaskopes sind nicht unbedeutend. Vor allem erfordert das Aufsetzen der
Hydrodiaskopes stets eine gewisse Menge von physiol. Kochsalzlösung, ferner entstellt der Apparat den
betreffenden Menschen ganz bedeutend, viel mehr als alle andere Brillengläser, drittens kommt beim
Tragen des Hydrodiaskopes die Akkommodation nur noch ganz ungenügend zur Geltung.” (41)
The blown contact shells of the Müller Brothers had the important esthetic advantage of
being invisible. They still had the relative disadvantage of the insufficiency of the optical
correction that was significantly inferior to that obtained with the hydrodiascope.
Subjective symptoms limited the wearing time of contact lenses, even if certain patients
reached records of 8 to 10 hours. The need for an assistant to put the contact shells in
and to remove them was also noted. In comparing the two methods of correction, the
author arrived at the conclusion that he had to decide in favor of the Müller Brothers’
contact shells from now on: “A nicely fitted contact glass can be worn in the human eye
for hours and even for days at a time without disturbance or with only very minor
irritation.” (42) Such was the end of the era of the hydrodiascopes.
218
The Era of Hydrodiascopes
2 - Discussion
The hydrodiascopes were in use only for a period of about twenty years and this occurred
principally at Berne. One can justifiably wonder what caused their relative
unsuccessfulness in spite of their having been shown to possess a certain technical,
physiological and optical value.
2. 1 – Technical aspects
Lohnstein’s Model
Lohnstein deserves the credit for having adapted Czermak’s orthoscope for the optical
correction of keratoconus. There is no doubt that Lohnstein’s hydrodiascope was
primitive, having an appearance and filling attachments that were hardly attractive.
Lohnstein dared to do something that no other ophthalmologist had ever previously
undertaken. He had the audacity to:
place a liquid in prolonged contact with the eye,
position a corrective lens on the front wall of an orthoscope,
fit the device inside the orbital margin, where it could rest on the eyelid periphery,
reduce the dimensions of Czermak’s device, thus improving optical correction.
Majeswski’s Model
Majewski’s model took its inspiration from Lohnstein’s hydrodiascope and preserved the
essential elements of the latter. Majewski should nevertheless be given credit for
introducing a connection between the two shells, thus creating, so to speak, “water
spectacles” for binocular correction of refractive errors.
Siegrist’s First Model
The basic Siegrist model was adapted from the orthoscope of Czermak, the deficiencies
of which he retained by applying it to the exterior of the bony orbital border with the
consequently imperfect water-tightness. Siegrist was apparently unaware of the
modifications that Hasner had applied to Czermak’s orthoscope with the intention to
adapt the latter for prolonged use.
Siegrist’s Ideal Hydrodiascope
The impetus given by Lohnstein’s hydrodiascope had allowed the Berne researchers to
develop a more perfect hydrodiascope equipped with an optical correction that could be
used on a daily basis by patients affected by keratoconus.
The Orthoscope and its Priorities
We must remember that neither Lohnstein nor Siegrist cited the priorities of Hasner,
Coccius or Gerloff, the orthoscopes of whom, after reduction of their diameters, as
compared with that of Czermak, also lay on the palpebral periphery. These orthoscopes
had water-tightness and functionality equivalent to those of Lohnstein’s hydrodiascope.
The merit of Lohnstein is that he inserted a corrective lens with adequate inclination and
refractive correction into the apparatus of his predecessors and thereby disseminated the
idea of optically correcting a deformed cornea.
219
The Era of Hydrodiascopes
2. 2 –Physiologic Aspects
Neutralization of Cornea by a Liquid
The idea of neutralizing the optical effect of the cornea by a liquid placed against it was
known to the scientific and medical community since the diffusion of Czermak’s idea by
Helmholtz and its being put into practice for contact lenses by Fick. Lohnstein,
nevertheless, asked himself the question of whether the refractive index of the liquid
should approach that of the cornea or the aqueous. His response was hesitant, but trial
and error demonstrated to him that corneal neutralization was reached under good
conditions with physiologic saline. Siegrist did, however, refer to the principal work of
Fick, from which he cited the paragraph on corneal neutralization by means of the
interposition of an intermediate liquid between the contact lens or shell and the ocular
globe.
The Quality and the Toleration of the Liquid
The episode of the hydrodiascopes allowed sufficient time for the clarification of those
disputes regarding the quality and the properties of the liquid to be used for filling the
hydrodiascope. Had Lohnstein asked himself the question of what the index of refraction
should be, he would surely have quickly decided on the 0.85% saline solution, the
refractive index of which was close to that of the aqueous humor and for which the
ocular tolerance appeared the best: “From an optics standpoint, namely with respect to
refractive index, the saline solutions I have chosen correspond with the aqueous humor.
[…] The aqueous humor approximates physiologic saline, its refractive index barely
different from our filling fluid, only to the fourth decimal point at the maximum. I have
deliberately avoided taking a refractive index of the latter identical to that of the cornea
because, both in keratoconus cases and in various cases of irregular astigmatism, a
better optical effect was achieved where the cornea has approximately the same
thickness in the transparent areas […]. Fick’s statement that a 2% grape sugar solution
has the same refractive index as the cornea is therefore not valid.” (43)
Majeswski followed suit. Fater tried several saline solutions, namely 0.75%, 0.88% and
1.39 %, the last supposedly corresponding with the dilution of human tears, but all
solutions proved to be intolerable. Ringer’s solution was the best tolerated. Lüdemann’s
studies in the Bern Eye Clinic referred solely to the use of physiologic saline.
The Optical Quality of the Surface acting as Substitute for the Neutralized
Cornea
The open orthoscope of Czermak and the closed version of Hasner were equipped with
a plano lens. Lohnstein equipped his hydrodiascope with a non-removable corrective
lens. Siegrist returned to the plano lens but added a detachable corrective lens, first fixed
by a screw-in attachment, later slipping along a slide to allow easier insertion and
removal. Lohnstein described his theory of the power of hydrodiascope lenses superbly
after 1897, to the extent that his successors were content to refer to his account without
questioning it. From that time on, it seems to have been accepted that the fundamental
advantage of the hydrodiascope, the one that allowed it to compete with contact lenses
and shells, consisted in the perfect correction of refractive errors and the resultant
normalization of visual acuity. All authors noted that this result was reached from the fact
that the hydrodiascope allowed the introduction of a new spherical surface of appropriate
power and that astigmatism was eliminated from the optical system formed by the eye
and the liquid.
220
The Era of Hydrodiascopes
Secondary Effects of the Hydrodiascope
Enlargement
The enlargement of the retinal image was generally noted by users of the hydrodiascope,
who emphasized that this effect (related to the lengthening of the optical system) was a
potential advantage for partially sighted persons.
Accommodation
The effect on accommodation had been noted from the first time that Lohnstein’s
hydrodiascopes were used. His successors referred to the effect without realizing that
they were attributing something to paresis or paralysis of accommodation that depended
on the optical system of an artificially elongated eye. The eye was thus furnished with
an approximate optical correction that solicited accommodation. Fater provided a
correct explanation for this phenomenon.
Corneal Edema
We learn that at the time of the controversy between Fick and Lohnstein, the latter had
observed objective signs of corneal edema at the time of an experiment with a 0.45%
saline solution: “I had a peculiar veil in front of my eye; […] a flame that I was
observing during this time showed weakly defined colored rings.” (44). This subjective
sign of corneal edema described by Lohnstein in 1897 was to be rediscovered in 1935 by
Sattler and to become “Sattler’s veil”, indicating corneal anoxia.
Cosmetic Handicap
The most important disadvantage of hydrodiascopes, one described by all authors,
resided in the difficulties encountered in positioning these devices on the eye with a large
volume of liquid, in addition to their unpleasing appearance.
2.3 – Other Applications for the Hydrodiascope
Correction of High Refractive Errors
Aside from his use of the instrument for the correction of keratoconus, Lohnstein had
proposed that hydrodiascopes could be used in patients for the correction of irregular
astigmatism and high myopia. Majewski had also used them in unilateral aphakia and in
severe regular astigmatism. Lauber found application for hydrodiascopes in the
correction of high myopia produced by peripheral corneal ectasia. The Berne School
appears to have restricted their application to patients with keratoconus.
Diagnostics and Research
The orthoscopes of Czermak and Hasner were used for diagnostics and research when
there was a need to neutralize the refractive power of the cornea for a brief period of
time. They were also used to eliminate reflections from the cornea in order to examine
the anterior ocular segment. Lohnstein’s hydrodiascope, equipped with a plano lens,
could be said to have taken over the next lap of an imaginary relay race towards the
finishing post of optical correction. In the course of his controversies with other
ophthalmologists, Fick drew attention to the fact that his contact lenses could also be
used for this purpose. Following the same line of thought, Lohnstein recommended his
hydrodiascope for diagnostic differentiation between visual disturbances of retinal origin
and those related to corneal irregularities in the assessment of retinal perception in a
patient with a corneal disturbance and in the early diagnosis of keratoconus. Lauber used
it in order to study the visual acuity of the eye after the elimination of corneal
irregularities.
221
The Era of Hydrodiascopes
Hydrodiascopes, Neutralization of Corneal Refractive Power and Contact Lenses
Lohnstein and Siegrist used hydrodiascopes eight years after the invention of contact
lenses and shells. Their application had the merit of provoking reflection and research
studies in regard to two essential points that hydrodiascopes had in common with contact
lenses. These were the neutralization of corneal refractive power by a compatible liquid
and the replacement of the corneal dioptric power thus neutralized by a new optical
structure.
The neutralization of corneal refractive power by a liquid was widely known within the
scientific community, particularly since Czermak’s orthoscope was described in
Helmholz’s treatise on physiological optics. Disagreement arose between the various
authors related to the nature of the liquid and its properties, both optical and metabolic:
Was it preferable to advocate, as Fick did, a liquid with a refractive index close to that
of the cornea or to follow Lohnstein and give precedence to the biological compatibility
of the liquid and its metabolic effects?
Was it preferable to correct the refractive error of the eye by a liquid lens, or would it not
be more appropriate to use a lens with refractive power situated within the body of the
device?
Hydrodiascopes have the following features in common with contact lenses:
immersion of the cornea in a liquid,
maintenance of the liquid in position by a specific device,
neutralization of the dioptric power of the anterior corneal surface,
centration on the optic axis,
correction of a refractive error by a new dioptric effect.
Hydrodiascopes are to be differentiated from contact lenses and contact shells essentially
by nature of their being positioned far anterior to the eye and by their contact to skin as
opposed to the cornea.
They also undoubtedly possess certain properties in common with contact lenses and
merit, therefore, to be cited among their forerunners. (45)
222
The Era of Hydrodiascopes
3 - Historical Survey of the Citations and
Misinterpretations
Usually, hydrodiascopes are ignored by historians of contact lenses or referred to
erroneously. (46) Even if these devices are not placed under the lids and are not in
contact with the eye, they possess, nevertheless, all the other characteristics of contact
devices and thus represent an important step forward in the history of neutralization of
corneal dioptric power.
Certain historians considered that the experiments of Young inspired Lohnstein and
Siegrist: “It is interesting that almost a century later [than Thomas Young], the same
idea was taken up in the hydrodiascope of Lohnstein of Berlin (1896-97) and Siegrist of
Switzerland in 1897 […;] at its best it was, of course, unwieldy and impracticable.”
(47).And also: “It is nevertheless worth mentioning that the design of Young found
application in refined form by Lohnstein and Sigrist [sic] around 1896 as ‘the
hydrodiascope’ for the correction of patients with refractive errors, which derive from
deformities or irregularities of the anterior surface of the cornea (regular and irregular
corneal astigmatism and keratoconus).” (48) This link with Young is arguable, as the
device used for the neutralization of his corneal dioptric power was not fixed to the head
and he plunged his head into it with the head inclined to the horizontal. (49) While
attributions of the priority of the concept of the hydrodiascope are generally ambiguous,
one notes attributions of the description of the principle of the hydrodiascope for
neutralization of corneal dioptric power to Descartes, La Hire and Hershell. In truth,
Lohnstein declared that he was inspired by Young’s experiment and by Czermak’s
orthoscope described by Helmholtz. The first instrument described by Siegrist recalls the
closed orthoscope of Hasner. The similarities between the hydrodiascope and the
orthoscopes of Czermak, their improvements by Hasner, Arlt and Coccius, and the
citation by Helmholtz are very rarely mentioned in the literature.
Conclusion
The orthoscope of Czermak, equipped by Lohnstein with a corrective lens under the
denomination of hydrodiascope, was completed by Majewski then perfected by Siegrist.
It facilitated the optical correction of several patients with keratoconus.
The first “water case” (Wasserkasten), that of Siegrist, did not pass the stage of isolated
clinical trials at the Berne Eye Clinic. Subsequently, very highly sophisticated
hydrodiascopes were manufactured by Bischhausen opticians in Berne, and their
commercialization was exploited up until 1910.
It is not surprising that the blown scleral contact shells of Müller Brothers, ocularists of
Wiesbaden, were substituted for the unwieldy and esthetically unpleasing
hydrodiascopes. This provides the greatest support for the conclusion that Siegrist gave
in regard to his last endeavor: “I am convinced that these modern contact-glasses will
make the hydrodiascope completely unnecessary and dispensable because it represents
only one step in our attempts to perfect our optical devices for the management of
keratoconus.” (50).
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The Era of Hydrodiascopes
Notes
1 In this chapter, we use often the terms “contact lens” and “contact shell” as generic synonym (ISO 8320: Contact lens: a generic
term including any lens designed to be worn on the front surface of the eyeball.) (See Appendix 10-1).
According to current terminology, the essential difference between a contact lens and a contact shell is that the former has a specified
front or back vertex power. Although a rigid contact shell has no specified power, it does allow the formation of a liquid lens that
will correct regular or irregular astigmatism and may also correct part of the spherical component of a refractive error. Thus, an afocal
contact shell is capable of providing reasonable visual acuity, especially in a condition such as keratoconus.
2 The terminology used for similar devices consisting essentially of watertight goggles filled with water varies for different authors
and eras, i.e., “Orthoskop” (orthoscope) for Czermak (1851), “Hydrodiaskop” (hydrodiascope) for Lohnstein (1896), “Wasserkasten”
(water case) for Fater & Siegrist (1906).
3 Czermak 1851, Hasner 1851, Coccius 1852 & 1853. For the history of the orthoscope see chapter IX: The Era of Orthoscopes.
4 Helmholtz, “Handbuch der Physiologischen Optik” 1864, (first edition) p. 14-15.
5 On November 1, 1895, Lohstein underwent cauterization of the summit of the cone in his left and more seriously affected eye. This
was the usual procedure performed at that time. Then, on the December 8, 1895, four weeks after the operation, tissue retraction
resulted in corneal perforation at the margin of the cauterized zone with loss of aqueous and a transitory flattening of the ectatic
cornea. This ectasia allowed him several days of vision. This was followed by a positively disabling cicatricial leucoma, which
reduced his visual acuity to 1/18. There was no longer any means available him to improve his visual acuity, and neither stenopaic
nor hyperbolic spectacle glasses were beneficial to him. The effectiveness of the latter would have required perfect centration on that
part of the cornea that remained transparent, and they would have functioned only while the corneal condition was evolving.
In his right eye, the appearance of keratoconus occurred later, in 1893. This eye developed a myopia of -5.00 diopters. Without
corrective glasses, the visual acuity in this eye also dropped to 1/18.
6 Lohnstein 1897, p. 408. Lohnstein cites Young and Czermak, but not Hasner, although Lohnstein borrowed the idea of the closed
orthoscope from Hasner. This orthoscope rested on the soft tissue surrounding the ocular globe and was provided with a filling hole
at the top that was closed by a stopper (see chapter IX: The Era of Orthoscopes).
7 Lohnstein 1896, p. 409.
8 Lohnstein 1896, p. 410-411.
9 Lohnstein 1896, p. 413. A 2% glucose solution has a refractive index of 1.335, which is approximately the same as that of tears
and aqueous (1.337). Such a solution is perfectly compatible with neutralization of anterior corneal refractive power, excluding
corneal thickness.
10 Lohnstein 1896, p. 417.
11 Lohnstein 1896, p. 417. Lohnstein also use the term “Contactglas”, as advocated by Sulzer, thereby demonstrating that he found
it just as suitable as Fick’s “Contactbrille”.’
12 “Vielleicht, dass man durch zweckmässigen zeitweiligen Gebrauch die Myopie zum Stillstand bringen kann.” (Lohnstein 1896, p.
418).
13 Lohnstein 1897, p. 133-134. Lohnstein reinvented the indications for Hasner’s (1851) and Coccius’s (1853) plane glass
orthoscopes used for ophthalmoscopy. Gerloff (1891) also used this device for fundus photography (see chapter IX: The Era of
Orthoscopes).
14 Lohnstein, 1897 & Fick, 1897. The elements of the controversy concerning Lohnstein’s criticism of Fick’s “Contactbrille” are
analyzed in chapter XIII: The Decades after the Invention.
15 Lohnstein 1897, p. 133-134.
16 Zehender in Lohnstein 1897, p. 133 footnote 1.
17 The text of this initial presentation was printed for the occasion of the inauguration of the Krakov Ophthalmological Clinic
(B.Wicherkiewicz “Wiadomosci z Kliniki okulistyczne” Krakov, 1898). Wicherkierwicz referred again to this publication in 1909,
when he took part in the discussion of Parisotti’s report to the French Society of Ophthalmology.
18 Majewski 1899, p. 162-163.
19 Majewski 1899, p. 163.
20 Majewski 1899, p. 164.
21 Fater 1906/a, p. 95-96 & Fater 1906/b, p. 5-6.
22 Fater 1906/a, p. 96 & Fater 1906/b, p. 6.
23 Ringer’s solution is an isotonic solution of chlorides of sodium, potassium, and calcium.
24 Fater was mistaken when she attributed accommodative weakness to deterioration from nonuse, following Lohnstein.
25 Fater 1906/a, p. 109 & Fater 1906/b, p. 19.
26 According to Helmbold, the hydrodiascope was used at the Koenigsberg University Eye Clinic in 1906. As Helmbold states: “bei
der Entlassung betrug die Sehschärfe rechts mit Siebbrille 2/35, links 5/25, mit Hydrodiaskop - +3 dpt sphär + 3dpt cyl, axe horiz
5/10” (At discharge, visual acuity reached 2/35 O.D. and 2/55 O.S. with stenopeic spectacles, 5/10 with the hydrodiascope (+3.00
D.S. +3.00 Cyl axis horizontal.) (Helmbold 1913/14, p 77)
This same patient was later one of the first to be fitted with contact lenses by Helmbold and wore these at least until 1920 (see chapter
XV: Early Blown Contact Lenses).
27 Lorenz 1908, p. 23-24.
28 “Les verres de contact et l’hydrodiascope sont des prothèses à essayer systématiquement.” (Terson 1909, p. 343-344).
29 Lauber 1909, p. 210. Communication to the Vienna Ophthalmological Society, May 12, 1909.
30 Uhthoff 1909, p. 48. Uhthoff did not know that in 1899 Majewski had described and used a binocular hydrodiascope.
31 Parisotti 1909, p. 87-88. The spellings “hydrodioscope” (for hydrodiascope) and “Jater” (for Fater) are incorrect.
32 Antonelli 1909, p. 147-148. Discussion of the annual report on “Keratoconus” at the 26th Annual Meeting of the French Society
of Ophthalmology (Société française d’Ophtalmologie) & Antonelli 1909, p. 252.
33 “L’hydrodiascope de Lohnstein perfectionné par mon ancien assistant, le professeur Majewski, relève la vision considérablement
et même donne une acuité visuelle de 6 à 8 dixièmes.” (Wicherkiewicz 1909, p. 180). Discussion of the annual report on
“Keratoconus” at the 26th Annual Meeting of the French Society of Ophthalmology.
34 “Lauber empfiehlt vor allem das Hydrodiaskop dazu, um dem Patienten zu zeigen, wie viel durch die zweckmässige Therapie
dieses Augenleidens zu ereichen ist.” & Lauber, in discussion of Krämer’s communication: “Es scheint mir gefährlich zu sein, dem
Kranken mit dem Hydrodiaskop etwas demonstrieren zu wollen, was er nach der Operation sehen werde.” (Krämer 1923, p. 372).
Communication to the Vienna Ophthalmological Society, June 19, 1923.
35 Krämer 1923, p. 244-245.
36 Siegrist 1916, p. 408.
37 Siegrist 1916, p. 410.
38 Siegrist designated the blown scleral contact shells of the ocularists Müller Brothers first by the term recommended by the
manufacturer, “adhesion-contact-spectacle” (Kontaktadhäsionsbrille). Later, he used the term “contact glass” (Kontaktglass).
39 Siegrist 1916, p. 420.
40 Lüdemann 1917/a, p. 284 & Lüdemann 1917/b, p. 20-21.
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The Era of Hydrodiascopes
41 Lüdemann 1917/a, p. 285 & Lüdemann 1917/b, p. 21.
42 “Ein gut passendes Kontaktglas kann vom menschlichen Auge stundenlang, ja tagelang ohne oder nur mit ganz geringen
Störungen getragen werden.” (Lüdemann 1917/a, p. 288 & Lüdemann 1917/b, p. 24).
43”In optischer Hinsicht, d.h. in Hinblick auf den Brechungsindex, entsprechen die von mir gewählten Kochsalzlösungen dem
Humor aqueus. […]. Da der Humor aqueus anährend die physiologische Kochsalzlösung ist, so ist sein Brechungsindex höchstens
in der vierten Stelle nach dem Komma von dem unserer Füllflüssigkeit verschieden. Absichtlich habe ich davon Abstand genommen,
den Brechungexponentens der letzteren gleich dem der Hornhaut zu nehmen, weil weder im Falle des Keratokonus noch in den
sonstigen Fällen von unregelmässigem Hornhautastigmatismus, wo die Hornhaut an den durchsichtigen Stellen annähernd gleich
dick ist, damit ein besseres optisches Effect erzielt würde. […]. Fick’s Angabe, wonach eine 2% Traubenzuckerlösung die gleiche
Brechung wie die Hornhaut hat, trifft also nicht zu.” (Lohnstein 1896, p. 412-413).
44 “Ich hatte einen eigenthümlichen Schleier vor dem Auge, […] eine Flamme, die ich während der Zeit betrachtete, zeigte schwach
angedeudete farbige Ringe.” (Lohnstein 1897, p. 133).
45 The hydrodiascopes have more features in common with contact lenses than Leonardo da Vinci’s masks or the tube of Descartes,
so often quoted by the historians of contact lenses.
46 Aside from mistakes in their patronyms: “Lohenstein” or “Loewenstein” (for Lohnstein) and “Giegrist” or “Sigrist” (for Siegrist).
47 Mackie in Duke-Elder 1970, p. 713. One finds other similar erroneous texts, e.g., in Mamolli 1931, p. 61-62.
48 “Es ist jedoch erwähnenswert, daß die Anordnung von Young in verfeinerter Form von Lohnstein und Sigrist (sic) um 1896 als
‘Hydrodiaskop’ zur Korrektion von Sehfehlern, die auf Deformationen oder Unregelmäßigkeiten der Hornhautvorderfläche
(regelmäßiger und unregelmäßiger Hornhautastigmatismus, Keratokonus) zurückzuführen sind, Anwendung fand.” (Baron 1981, p.
3).
49 See chapter VII: Corneal Immersion by Thomas Young.
50 “Diese moderne Kontaktgläser werden nach meiner Ueberzeugung das Hydrodiaskop, welches nur eine Stufe in der
Vervollkommungsbestrebung unserer optischen Hilfsmittel gegen Keratokonus darstellt, vollkommen unnötige und entbehrlich
machen.” (Siegrist 1916, p. 420).
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The Era of Hydrodiascopes
226